


A vow for just Us

by Sweetsensation



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe - Canon Divergence, Creampie, Cunnilingus, F/M, Hurt/Comfort, Male My Unit | Byleth, Marriage Proposal, Pre-Time Skip, Vaginal Sex
Language: English
Status: Completed
Published: 2020-01-14
Updated: 2020-01-14
Packaged: 2021-02-27 12:07:48
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,989
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22256935
Author URL: https://archiveofourown.org/users/Sweetsensation/pseuds/Sweetsensation
Summary: Berni is conflicted by her crush one Byleth but comes to find out that her dear professor has been holding back some feelings as well. In the dead of night, they decided to make a vow just for the two of them.
Relationships: My Unit | Byleth/Bernadetta von Varley
Kudos: 44





	A vow for just Us

**Author's Note:**

> the part of this that makes it Au is the early relationship pre-end of game.

Bernie sat in bed, she held tight to her stuff bear as the rain came down. Even though she had been working with Byleth to get over her anxiety, the rain and thunder still scared her. Bernie was very thankful for the professor’s work with her. Even nights like this he would check on her to see if she was doing okay. Though tonight it would be unlikely, Byleth had been distant ever since Jeralt was killed a few weeks ago. 

Bernie wished she could have done more for her teacher, he meant a lot to her. He would give her gifts like the stuffed bear she held on to, as well as plants and flowers from the garden. Though it wasn’t his expertise he would listen to her love for carnivorous plants, and he was the only one she really had opened up about her family. It wasn’t long till Bernie realized that she loved the Professor, but like most things was worried about it. 

As she squeezed the bear tight as the thunder clapped in the sky. She couldn’t help but let out a horrible scream. She took deep breaths trying to recover when she heard a knock coming from the door. 

“Who is it?” She barely got out as her voice shook. 

“It’s Byleth, I..I came to check on you” 

Before even thinking the purple-haired shut-in raced to the door opening it. There she saw her professor, and crush soaked by the rain. “May I come in?” He was as blunt as usual not being the most charismatic person. 

“Um Yes, of COUUUUUUUURSE AHHHH” she screamed as the thunder rang out. 

Bernadetta slowly stopped wincing as she felt his arms around her in an embrace. He was cold and wet from the rain. But together they moved inside the room. The young girl swerved her head trying to find a towel for him. She finally saw one and handed over, without think Byleth began to take off his shirt and pants as they were soaking. Her face began to turn bright red. 

“UM, Pr..Pro...professor!” She let out with a stutter. She couldn’t help but stare at his muscles that came from years of training. 

“Oh! Sorry, Bernadetta, I wasn’t thinking. Is it okay if I borrowed a blanket to cover up with till my clothes dry.” He says realizing his own nudity.

She just nods as she can’t help but stare, but slowly she gets more anxious. What if he catches her looking, what if she thinks she is weird, her life would be over and the only one she would have ever loved will hate her. Her body starts to shack before once again she feels something embrace her. This time it’s warm and soft. But she soon realizes that she is pressed right against Byleth’s chest. Her hands can feel the soft skin and toned body; her face got more red. 

With all the newfound nerves thanks to the professor, she had just forgotten about the storm outside. Until a loud boom caused Berni grabbed on to Byleth with all her strength. 

“It will be okay, I won’t let anything hurt you,” He said calmly, slowly rubbing her back. “Berni, can you look up at me?” He asked.

Slowly she turned up to see his natural straight face. “Yes Professor?”

“I’ve told you, you can call me Byleth. I’m not really a professor.” 

Bernie knew these but she knew everyone else called him that and didn’t want to be standing out. 

“Yes, Byleth?” Her face was still red.

“Do you mind if we sit down, I have something I want to talk about?” 

“Why? Did I do something wrong? I’m in trouble, aren’t I? Bad Bernie?” She squirmed about until she felt the embrace tightened and she slowly calmed down. 

“Nothing is wrong, but it is something important.”

The two made their way to the edge of the bed. Byleth had wrapped himself in the blanket in covers. 

“Pro-Byleth can I ask a question first?”Byleth nodded. “To be honest, I’m surprised you came tonight. Though you have helped me in the past. You have been preoccupied lately... so why tonight?”

She looked at her teacher, his bright green hair that almost seemed to glow and his eyes that reached her soul. They were filled with something she couldn’t tell almost as if two souls were watching her. “Well, that is why I asked us to sit down.” Byleth took a deep breath. “My father left me his journal, and recently I have been reading it. He talked about how he wanted me to find someone I loved and cared about deeply. He even brought up marriage.” 

Bernie wasn’t sure why he was telling her this. She had never really seen her teacher open like this before in all their times talking. But she could feel her chest tighten and heart beat faster. “Byleth why are you telling me this?”

“Because after a lot of thinking, I’ve realized I love you Bernadetta”

The words flowed smoothly from his lips. Bernie didn’t know how to react to the one she loved feeling the same way. She blanked for a second before snapping back into reality. 

“Did you just say you love me?!”

“I did, I understand that you are technically my student. But I want to protect you, and be there for you and help overcome all that comes in your way.” As Byleth said this Bernie’s heart began to be faster and faster. 

Taking every ounce of courage she had she pushed herself forward. Her lips pressed against his. Her anxious thoughts began to wash away as she began to give in to this new warmth. They slowly separated. 

“I felt something for you for a while now, Byleth. I was worried that because of your position as my teacher you would never see me in that way or you would just view me as a bother.”

“You are never a bother,” he said brushing her messed up hair.

Bernie has completely forgotten about the storm outside her only focus was on her knee lover.

“My father did also give me a ring.. I think I want to give it to you.”

“Like.. marriage... this is so sudden.. I’m still in school... people would find out?” She said in haste before Byleth had taken her hands. 

“I know, so I will wait till you graduate, then I will officially take you as my bride if you desire.” 

Tears began streaming down her eyes, Bernie was always scared about being forced into marriage because of her father but know she could marry the man she wanted, who wanted the best for her, not the bloodline. Some part of Bernie didn’t want to wait, knowing these fights any day could be their last.

“Even without a ring, or anyone to watch us. Could we get married now? Just the two of us, any day we...could die. I want to be with you forever.” 

“Yes, we can, something that’s for us alone!” Byleth wiped her tears and took the blanket off himself putting it on Bernie’s head like a veil. 

Their eyes met, and things slowed down. Their hands still holding each other. “Bernadetta, do you take me to be your husband. To cherish and hold for the rest of your life?” 

“I do!” Tears began to fall again. “Do you Byleth, take me to be your wife? To guide me and protect me for the rest of your life?”

“I do” There was a pause, as the two took in the process that just happened. “I love you Bernadetta!”

“I love you too” 

With no need for words, the two gave into a deep kiss. Their union was set in place for them as they in their hearts become one. The outside world meant nothing to them. Bernie felt her body slow down no longer filled with anxious thoughts. Each second a new feeling of warmth took over her. She leaned forward, her body pressing into his chest as each kiss became more passionate. She could feel his arms wrap around her body holding her close. 

Bernadetta felt his soft hands slowly work their way under her shirt. She without thinking let out a soft humming moan as she felt his hands. The kissing had began to be more disorganized as she began to give into the new sensation of his gentle touch on her body. She could feel his hands work up her small body. Instinctually she lifted the shirt off revealing her bare chest. 

Things began to sink in, her heart began to race faster. Self-doubt about her image flashed in her mind. She stopped and looked in her new husband’s eyes. She knew that look, it was the same look he had when visiting his mother’s grave. It wasn’t sadness but overwhelming compassion and love. There was a silence all that could be heard was the soft patter of rain. 

“You’re Beautiful” was that escaped Byleth’s lips. 

The words were soft and sweet just loud enough for Bernadetta to hear. 

Once more her eyes began to tear up. She was just too happy to control it. The only man she ever loved, felt for her the same day. She couldn’t get over how he didn’t want her for her title or care that she had anxiety. He loved her and thought she was the most beautiful thing in the world. She felt his soft hands cup her face, soothing her. 

“I love you!” She squeaked. “And I want to give you all of me, my husband.” The last word she heard ring out almost unnaturally as though the weight sunk in.

“I want you to have all of me as well, my dear wife” 

Before she knew it, their lips were together again. His hands slowly moved to her small breast, as he caressed them she let out moans of pleasure. Soon she felt him begin to cover her neck in kisses, tingles began to cover her body; which felt the careful attention he took in loving her. Her body began to relax more and more melting in pleasure. She could feel her body get more aroused. 

As her eyes shut giving into each kiss each on leaving more to be desired. Bernie felt his hands move from her breast to her shoulders. She gave her lover full control as she followed his guidance as he laid her back on the bed. As their lips broke apart she looked into his eyes, they exchanged a brief smile to one another. It didn’t hit Bernie till a second later that this was a rare occasion to see him smile. 

They both took deep breaths before Byleth made his way down her body his mouth kissing her torso making it all the way to her slim stomach. Bernadetta felt her heartbeat in anticipation as he got closer to her yearning womanhood. She felt his hands slip under the waistband of her underwear. Her hands gripping the sheets, she looked and gave him a nod to continue. 

She felt almost a slight chill come over her as she was fully exposed. But she didn’t care she was ready for him to be with all of her. No hiding or running just two souls acting as one. She let out a soft “eep” as he kissed her inner thigh working his way in. Each kiss melted Bernie more and more. It was almost strategic as he pleasured her womanhood. As he continued she let out a moan after moan, each one more resonating. She felt his tongue begin to explore her folds, she gripped the sheet tighter as she felt her body react in ecstasy to the pleasure. “Byleth, please you can go a little faster. It feels really good” she let out.

Without saying a word complied and began kissing her clit, and licking it with fast short strokes. Her breath started to match the pace, quick gasps as her body tightened melting her with feelings of pleasure. He didn’t tease her, which she was glad. Bernie felt as though she was truly apart of something she wasn’t scared of. Her lover complied with her needs not his owns to send her to a state of bliss. 

It wasn’t long before she couldn’t handle it much longer. She felt her body tighten. Her legs shook as her body was met with a wave of intoxicating pleasure. 

“Byleth I’m..” She could finish before letting of a deep moan signifying her orgasm. 

Bernadetta took deep breaths as she tried to recover. She hadn’t felt pleasure like that before. 

In a pant, she said, “I’m sorry I didn’t give you more warning”. 

She leaned up looking at her love who though didn’t really have a smile like earlier she could tell was happy. In a calm voice, he crawled next to her.

“It’s okay, you are still new to this. I just want you to feel good, and I can tell you did. Am I right?” 

Bernie nodded still catching her breath. She wanted him to feel good too though. 

She cupped her hands around his face pulling him closer, and with a chaste kiss said, “I want us to be one flesh, please let me make you feel good too”. 

The normally anxious girl felt at peace her fears and worries had subsided in the heat of their love. 

Byleth gave her a kiss back Before removing his undergarments revealing his erect member. Bernie wasn’t sure what to think this was her first time really seeing a penis in person. Her body still wet from before was ready for the next step. 

“I’m going to start gently okay?” Byleth said slightly teasing her entrance.

“Yes, I'm ready” some of her nervous had returned but soon went away. 

She felt her body expand as his shaft slowly entered her, she felt a slight pain but not much. Soon she could feel all of him inside her, she had never known a beauty such as this. Bernadetta felt as though her and Byleth were connected body and soul. 

“You can start moving,” she said still taking the bliss in. 

Slowly at first, she felt him move in and out, she felt her body wrap around him as if it was made for him alone. She gripped the sheets again letting out pants and moans. She wasn’t worried about volume because of the storm. Soon she felt his arms around her and his soft lips on hers. She could feel the vibrations of hushed moans coming from his lips. Each kiss became more passionate as they felt their bodies fall into a rhythm. 

Barley breaking away Bernadetta cuts through the moans saying “okay, I’m ready for you to go harder”. 

She felt safe her teacher turned secret husband actions as he sped his hips up.

Each thrust wrapping her in more and more pleasure. Her legs wrapped around him, holding him close to her. She wanted this moment to never end as she gave more into the pleasure. Her mind melted as their tongues met with each kiss. Soon her hand felt his on to of it as she gripped the sheet. Slowly she let go in exchange for the soft hand of her partner. 

Bernie could feel him reaching all of her sensitive spots. Her womanhood tightened around his member keeping it inside as if it too didn’t want to part from the lover. Her back began to arch as she felt the pleasure build inside of her. 

In hot breaths Byleth let out “Bernadetta, I’m close.”

“I am too, please finish inside.” She moaned back. 

The two gave a chaste kiss and parted saying “I love you” to each other. Byleth let out a deep moan, as Bernie felt warmth fill her body causing her body to orgasm. She let out a louder than normal moan that was stopped by a kiss, that pulled her back to reality from the ecstasy. 

Bernadetta felt his embrace leave as he pulled out of her and rolled on to the bed. She could feel her heart pound in excitement as she thought about what had happened. But then thoughts of everyone finding out sent her of a frenzy of fear. She felt a slight tug and before she knew it she was pressed against Byleth’s body. 

“It will all be fine, I’ll make sure no one knows. It is my job to take care of my wife is it not?” She felt his lips on her forehead. 

She took a deep breath as she calmed down. 

“And I’ll do my best to protect you! My husband, we will protect each other.” Byleth nodded in agreement. “Can you please stay with me tonight?” She added.

“Of course, but in the morning. You need to leave first. So when I leave I can lie and say I was doing a dorm inspection.” Byleth replied.

“Thank you... my husband” she leaned up to give him a kiss.

The two then used towels to clean up, as they were now covered in a mix of each other’s sweat and love juices. 

“I don’t mean to cause panic, but aren’t you worried about getting pregnant?” Byleth asked.

“No, I take these contraceptive herbs for my period, so they should block against that risk. Though in the future .. I wouldn’t mind having children.” Her voice became more nervous at the end.

“I agree it would be nice, though it will be a shame my parents won’t be able to meet them” Byleth got quieter than usual. 

Before turning to Bernie “now let’s get some sleep.” 

Bernie nodded as she put her shirt back on before getting in bed, taking in the warmth of his embrace. The two exchanged a final kiss and goodnight before drifting to sleep now as one body and one soul.


End file.
